The following relates generally to wireless communication, and more specifically to channel clearance techniques using shared radio frequency spectrum band.
Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). Examples of such multiple-access systems include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, and orthogonal frequency division multiple access (OFDMA) systems, (e.g., a Long Term Evolution (LTE) system). A wireless multiple-access communications system may include a number of base stations, each simultaneously supporting communication for multiple communication devices, which may be otherwise known as user equipment (UE).
In some wireless communication systems, base stations and UEs may communicate over a radio frequency spectrum band using different types of component carriers (CCs), such as enhanced component carriers (eCCs) or non-eCCs. When base stations and UEs communicating via different types of CCs share a radio frequency spectrum band, or when base stations and UEs share a radio frequency spectrum band with devices using other types of communications, techniques may be employed to avoid, mitigate, or cancel interference caused by use of the different types of CCs or communication technologies. For example, devices using a shared radio frequency spectrum band may perform a listen-before-talk (LBT) procedure in which a device, such as a UE or a base station, may monitor a channel to identify whether any other devices are transmitting on the channel, and use the channel for transmission if the channel is clear. When transmitting between a base station and one or more UEs, each device may experience different channel conditions, and in some cases a base station may determine a channel is clear when a UE may experience interference from another device on the channel.